From 36a24c7881427d2e1e4dc1cef58f19eee0d13aec Mon Sep 17 00:00:00 2001
From: David Bryant <david@wavpack.com>
Date: Sat, 10 Feb 2018 16:01:39 -0800
Subject: [PATCH] issue #28, do not overwrite heap on corrupt DSDIFF file

Fixes CVE-2018-7253

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
---
 cli/dsdiff.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/cli/dsdiff.c b/cli/dsdiff.c
index 410dc1c..c016df9 100644
--- a/cli/dsdiff.c
+++ b/cli/dsdiff.c
@@ -153,7 +153,17 @@ int ParseDsdiffHeaderConfig (FILE *infile, char *infilename, char *fourcc, Wavpa
                 error_line ("dsdiff file version = 0x%08x", version);
         }
         else if (!strncmp (dff_chunk_header.ckID, "PROP", 4)) {
-            char *prop_chunk = malloc ((size_t) dff_chunk_header.ckDataSize);
+            char *prop_chunk;
+
+            if (dff_chunk_header.ckDataSize < 4 || dff_chunk_header.ckDataSize > 1024) {
+                error_line ("%s is not a valid .DFF file!", infilename);
+                return WAVPACK_SOFT_ERROR;
+            }
+
+            if (debug_logging_mode)
+                error_line ("got PROP chunk of %d bytes total", (int) dff_chunk_header.ckDataSize);
+
+            prop_chunk = malloc ((size_t) dff_chunk_header.ckDataSize);
 
             if (!DoReadFile (infile, prop_chunk, (uint32_t) dff_chunk_header.ckDataSize, &bcount) ||
                 bcount != dff_chunk_header.ckDataSize) {
-- 
2.11.0